Mineraloške i sedimentološke karakteristike željezove rude u povijesnom rudniku Kotlenice

master's thesis

• Title: Mineraloške i sedimentološke karakteristike željezove rude u povijesnom rudniku Kotlenice : diplomski rad
• Title (english): Mineralogical and sedimentological characteristics of iron ore from historical mine Kotlenice : master's thesis
• Author: Filip Presečki
• Mentor: Goran Durn (mentor)
• Committee member: Goran Durn
• Committee member: Marta Mileusnić
• Committee member: Uroš Barudžija
• Granter: University of Zagreb; Faculty of Mining, Geology and Petroleum Engineering; (Department of Mineralogy, Petrology and Mineral Resources); Zagreb
• Defense date and country: 2010-11-26, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Geology; Mineralogy and Petrology

Abstract

Cilj ovog rada bio je odrediti mineraloške, sedimentološke i geokemijske značajke željezove rude te njene
krovine i podine iz ležišta u starom rudniku u Kotlenicama kod Trilja, u zaleđu srednje Dalmacije u Hrvatskoj.
Željezova ruda nastala je na uzdignutoj karbonatnoj platformi na prijelazu iz donje u gornju kredu tijekom
emerzije, čije trajanje nije sa sigurnošću utvrđeno. U podini rude nalaze se mikritni vapnenci s fenestralnom
građom. Tijekom emerzije na izdignutoj karbonatnoj platformi razvijala su se lateritna tla koja su procesima
trošenja spirana u depresije paleoreljefa. Željezova ruda nastala je u specifičnoj, lokalno ograničenoj sredini u
kojoj su vladali reduktivni i slabo kiseli geokemijski uvjeti (npr. jezero, močvara ili bara). Krovinske naslage
čine sitnozrnasti, djelomice rekristalizirani crvenkasti mikritni vapnenci, impregnirani goethitom i hematitom iz
željezove rude koja je trošena kada je nastupila transgresija.
Mineralne faze koje dominiraju u željezovoj rudi su goethit i hematit. Od dna prema vrhu profila
željezove rude generalno raste udio glinovite komponente koju čine kaolinit, tinjčasti minerali, 14 angstremski
filosilikati i nepravilno interstratificirani minerali glina. U gornjem dijelu sloja željezove rude utvrđen je gibbsit.
Kao minorne mineralne faze u rudi se još javljaju anatas i kalcit. Nalaz gibbsita i kaolinita ukazuje da je lateritno
tlo nastalo na uzdignutoj karbonatnoj platformi, procesima trošenja spirano u depresije paleoreljefa u kojima su
vladali reduktivni uvjeti. Rezultati kemijske analize glavnih elemenata dobro se poklapaju s rezultatima
istraživanja mineralnog sastava rude. Distribucije elemenata u tragovima i elemenata rijetkih zemalja po profilu
željezove rude ukazuju na reduktivne i slabo kisele geokemijske uvjete koji su vladali za vrijeme nastanka
željezove rude. Visoke koncentracije nekih elemenata u tragovima (poglavito vanadija) vjerojatno indiciraju da
su procesi biomineralizacije odigrali važnu ulogu u nastajanju mineralnih faza željeza.

Abstract (english)

Abstract: The aim of this thesis was to define mineralogical, sedimentological and geochemical characteristics of
iron ore and its underlying and overlying carbonate sediments from the historical mine Kotlenice near Trilj in
the hinterland of middle Dalmatia, Croatia. Iron ore was formed on the uplifted carbonate platform during the
emersion phase in the transition from lower to upper Cretaceous. The duration of the emersion phase can not be
determined with certainty. The bedrock of iron ore is composed of micritic limestones with fenestral fabric.
Lateritic soils formed on the uplifted carbonate platform during the emersion phase were weathered, transported
and deposited in the depressions of the paleorelief. Iron ore was formed in specific, locally restricted
environment, in which reductive and slightly acidic geochemical conditions prevailed (e.g. lake, swamp or
marsh). Overlying sediments are composed of fine grained, partially recrystalized reddish micritic limestones
impregnated by goethite and hematite originated from iron ore, which was weathered during the transgression.
Dominant mineral phases in the iron ore are goethite and haematite. From the bottom to the top of iron
ore profile the amount of clay minerals, which are mainly kaolinite, mica minerals, 14Å philosilicates and
irregulary interstratificated clay minerals, is generally increasing. In the upper part of iron ore profile gibbsite
was determined. Minor mineral phases found in ore are anatase and calcite. The presence of kaolinite and
gibbsite may indicate that the lateritic soils formed on the uplifted carbonate platform were weathered and
transported into the depressions of the paleorelief in which reductive conditions prevailed. The results of
chemical analysis of major elements are in good corellation with the results of mineralogical analyses of ore.
Trace elements and rare earth elements distribution along the iron ore profile implicates that reductive and
slightly acidic geochemical conditions prevailed during the formation of iron ore. High concentrations of some
trace elements (in particular vanadium) probably indicate that the processes of biomineralization might have had
significant influence on the formation of iron mineral phases.

• Keywords: željezova ruda; goethit; hematit; kreda; emerzija; Kotlenice
• Keywords (english): iron ore; goethite; hematite; Cretaceous; emersion; Kotlenice
• Language: croatian
• URN:NBN: urn:nbn:hr:169:568551
• Study programme: Title: Geology; specializations in: Geology of mineral resources and geophysical explorations; Course: Geology of mineral resources and geophysical explorations; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra geologije (magistar/magistra geologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2016-03-29 08:37:43